AM Radio Reception?

[ray66v]

If they ever finally decide to quit playing around with 1920 technology, and digitize the AM band, it will be as good as, or better than FM in sound quality. And, it can have many more channels.

There have been proposals and discussions concerning this, but so far no real progress.

 

[Sawyer Rob]

Of the few CDs I own, I think there is one song per disk I like. I have a lifetime subscription to XM. Not sure I would pay for it at this point. Mostly listen to Patriot Radio, but you do get kind of sick of them preaching to the choir. What's the point? We have a local community radio station that plays better music thean XM, but they have limited range.

What kind of music do you like that's not on XM?? I listen to XM6 mostly, sometimes XM18 and sometimes XM5 or 7...

There's every kind of music on XM, and I listen to it more than any other stations...

SR

 

[Sawyer Rob]

Folks. No politics. No Rush. No. No. No..... NOooooooooo..........

Or the thread will be closed.

You mean, just mentioning how many listeners Rush has, will get a thread closed???

Why would that be??

SR

 

[Fuddy1952]

You can't mention anyone who receives The Presidential Medal of Freedom is why.

 

[JethroB]

What kind of music do you like that's not on XM?? I listen to XM6 mostly, sometimes XM18 and sometimes XM5 or 7...

There's every kind of music on XM, and I listen to it more than any other stations...

SR

I signed up for XM radio a few years ago for my company car set and my pickup. Quite nice for the variety and commercial free aspect. I had read about their automatic renewal tactics so I always paid by check, not credit card. They REALLY wanted that credit card number, ha. That turned out to a very be wise move. Every year at renewal time it was a fight to keep the fees from more than doubling. I held firm with keep it under $100 or cancel. And they made canceling difficult too. Four years later and I still get renewal offers.

 

[forestcreature1]

total lack of FREE music is why I don't use XM [I also don't have cable tv, etc.]
There is nothing happening on XM that is worth money to me.

 

[flyerdan]

I've got a pretty good testbed that illustrates how dirty AM has got over the years. It's a 30 some odd year old clock radio, set to 1190 KEX, never moves, never changes. When you hit the sleep button, you get an hour of audio, at night it's crystal clear and unwavering. During pauses there is no background noise at all. When the alarm goes off in the morning, you can hear the static bed, and sometimes during the summer the interference was so great you could barely make out what was said. Nothing in the house or shop electric draw changes during that time, except the coffee maker, and that has been eliminated as an interference source.

 

[bunyip]

am is susceptible to interference from the sun which is why it is quiet at night, just can't recall which radiation spectrum but thinking uv.

 

[k0ua]

am is susceptible to interference from the sun which is why it is quiet at night, just can't recall which radiation spectrum but thinking uv.

Well, it is a VERY complicated subject. But the gist of it is that the ionosphere consist of so called Layers that are formed by solar radiation. During the day, the formation of the D layer(I am simplifying here) acts as an absorption medium for frequencies below the MUF or Maximum Usable Frequency. This D layer absorption is what prevents these lower frequency waves from getting thru the D layer(s) to hit the F layers which are much higher up in the ionosphere that would allow these frequencies to refract back down and be propagated long distances. As soon as the sun stops illuminating this area then the D layer disappears, and long range propagation is again available. Now all that said there are MANY other factors at work here, but the formation of the D layer during the daytime is why you have to rely on the short range of ground wave propagation for these lower frequencies.

Night time propagation of AM broadcast band signals are not necessarily quiet, as local and regional thunderstorms static crashes can severally impact reception. Keep in mind that these lightning crashes themselves are propagated by ionospheric diffraction. So depending on where these storms are located they may or may not be heard regionally or even worldwide. Of course depending which hemisphere you are in, you may be going into a more noisy period, like you are down under with your summer time and more storm season coming on, and we up here in the northern hemisphere are coming into a more quiet time with our winter coming on.

As said, all of this is an extreme simplification of a complicated subject. One could study radio wave propagation all of their life and still not have a complete understanding of all of it.

 

[k0ua]

I've got a pretty good testbed that illustrates how dirty AM has got over the years. It's a 30 some odd year old clock radio, set to 1190 KEX, never moves, never changes. When you hit the sleep button, you get an hour of audio, at night it's crystal clear and unwavering. During pauses there is no background noise at all. When the alarm goes off in the morning, you can hear the static bed, and sometimes during the summer the interference was so great you could barely make out what was said. Nothing in the house or shop electric draw changes during that time, except the coffee maker, and that has been eliminated as an interference source.

As you may have noticed the noise floor has been slowly and in the last few years not so slowly rising worldwide. This is a pollution problem that very few are taking seriously. When our air quality degrades from particulate pollution or our water is filled with chemicals a lot of people get interested very quickly. When we continue to pollute the RF spectrum with cheap Chinese electrical devices, no one seems to notice or just shrugs their shoulders. Even Governmental agencies that are charged with setting and enforcing standards seem to let a lot of things slip thru and under the wire without comment or much action.